code: def test_mask(self):
      for p in TEST_NDARRAYS:
          img = p([[[0.0, 1.0], [2.0, 3.0]]])
          mask = np.array([[[1, 0], [1, 0]]], dtype=bool)
          img, meta_dict = IntensityStats(
              ops=["max", "mean"], key_prefix="orig"
          )(img, mask=mask)
          np.testing.assert_allclose(
              meta_dict["orig_max"], 2.0, atol=1e-3
          )
          np.testing.assert_allclose(
              meta_dict["orig_mean"], 1.0, atol=1e-3
          )
  
file_path: MONAI/tests/test_intensity_stats.py
imports: from __future__ import annotations
  import unittest
  import numpy
  from parameterized import parameterized
  from monai.transforms import IntensityStats
  from tests.utils import TEST_NDARRAYS
label_desc: Use image node_id 2 for calling the TestIntensityStats obj's underlying member method code with example usage: obj.test_mask() without return types